Multivariate evaluation of the effectiveness of treatment efficacy of cypermethrin against sea lice (Lepeophtheirus salmonis) in Atlantic salmon (Salmo salar)

Background: The sea louse Lepeophtheirus salmonis is the most important ectoparasite of farmed Atlantic salmon (Salmo salar) in Norwegian aquaculture. Control of sea lice is primarily dependent on the use of delousing chemotherapeutants, which are both expensive and toxic to other wildlife. The method most commonly used for monitoring treatment effectiveness relies on measuring the percentage reduction in the mobile stages of Lepeophtheirus salmonis only. However, this does not account for changes in the other sea lice stages and may result in misleading or incomplete interpretation regarding the effectiveness of treatment. With the aim of improving the evaluation of delousing treatments, we explored multivariate analyses of bath treatments using the topical pyrethroid, cypermethrin, in salmon pens at five Norwegian production sites.Results: Conventional univariate analysis indicated reductions of over 90% in mobile stages at all sites. In contrast, multivariate analyses indicated differing treatment effectiveness between sites (p-value < 0.01) based on changes in the proportion and abundance of the chalimus and PAAM (pre-adult and adult males) stages. Low water temperatures and shortened intervals between sampling after treatment may account for the differences in the composition of chalimus and PAAM stage groups following treatment. Using multivariate analysis, such factors could be separated from those which were attributable to inadequate treatment or chemotherapeutant failure.Conclusions: Multivariate analyses for evaluation of treatment effectiveness against multiple life cycle stages of L. salmonis yield additional information beyond that derivable from univariate methods. This can aid in the identification of causes of apparent treatment failure in salmon aquaculture

Statistical and ecological challengesof monitoring parasitic salmon lice infestationsin wild salmonid fish stocks

-Ecological monitoring programmes should provide precise data to inform management, but the data quality is often limited by methodological challenges and the need for cost-effective sampling. Parasite infestations are particularly challenging to monitor due to complex interactions among hosts, parasites and the environment. In Norway, salmon lice infestations on wild salmonid fish have been monitored since 1992 to survey the potential transmission between farmed and wild salmonids. Here, we compared spatiotemporal variation in salmon lice levels with variations in local fjord conditions, including salinity, temperature and infestation pressure from salmon farms (measured as mean abundance of mature female lice × number of farmed fish). We tested 3 different measures of infestation with different statistical properties. Our results confirm that, even after correcting for temperature and salinity effects, in - festation pressure from salmon farms significantly increases the probability of lice infestation in wild salmonids. The probability of infestation increases with fish body length, salmon farm infestation pressure and tem perature, and decreases with increasing freshwater influence. Furthermore, we found a significant interaction between temperature and infestation pressure from salmon farms. When the infestation pressure from farms is low, temperature has a strong increasing effect on the probability of infestation, but as the infestation pressure from farms increases, temperature gradually becomes less important. The exact results vary somewhat depending on the measure of lice infestations used, but the same trend can be seen in all models. We discuss the statistical and biological complexities that make monitoring of salmon lice in wild populations challenging

Sea lice as a density-dependent constraint to salmonid farming

Fisheries catches worldwide have shown no increase over the last two decades, while aquaculture has been booming. To cover the demand for fish in the growing human population, continued high growth rates in aquaculture are needed. A potential constraint to such growth is infectious diseases, as disease transmission rates are expected to increase with increasing densities of farmed fish. Using an extensive dataset from all farms growing salmonids along the Norwegian coast, we document that densities of farmed salmonids surrounding individual farms have a strong effect on farm levels of parasitic sea lice and efforts to control sea lice infections. Furthermore, increased intervention efforts have been unsuccessful in controlling elevated infection levels in high salmonid density areas in 2009–2010. Our results emphasize host density effects of farmed salmonids on the population dynamics of sea lice and suggest that parasitic sea lice represent a potent negative feedback mechanism that may limit sustainable spatial densities of farmed salmonids

Salmon lice (Lepeophtheirus salmonis) in the stomach contents of lumpfish (Cyclopterus lumpus) sampled from Norwegian fish farms: Relationship between lice grazing and operational conditions

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Relevance of Biomarkers in Serum vs. Synovial Fluid in Patients with Knee Osteoarthritis

The association between structural changes and pain sensation in osteoarthritis (OA) remains unclear. Joint deterioration in OA leads to the release of protein fragments that can either systemically (serum) or locally (synovial fluid; SF) be targeted as biomarkers and describe structural changes and potentially pain. Biomarkers of collagen type I (C1M), type II (C2M), type III (C3M), type X (C10C), and aggrecan (ARGS) degradation were measured in the serum and SF of knee OA patients. Spearman’s rank correlation was used to assess the correlation of the biomarkers’ levels between serum and SF. Linear regression adjusted for confounders was used to evaluate the associations between the biomarkers’ levels and clinical outcomes. The serum C1M levels were negatively associated with subchondral bone density. The serum C2M levels were negatively associated with KL grade and positively associated with minimum joint space width (minJSW). The C10C levels in SF were negatively associated with minJSW and positively associated with KL grade and osteophyte area. Lastly, the serum C2M and C3M levels were negatively associated with pain outcomes. Most of the biomarkers seemed to mainly be associated with structural outcomes. The overall biomarkers of extracellular matrix (ECM) remodeling in serum and SF may provide different information and reflect different pathogenic processes

A global experiment on motivating social distancing during the COVID-19 pandemic

Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e., a controlling message) compared with no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared with the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing. Controlled motivation was associated with more defiance and less long-term behavioral intention to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

A global experiment on motivating social distancing during the COVID-19 pandemic

Finding communication strategies that effectively motivate social distancing continues to be a global public health priority during the COVID-19 pandemic. This cross-country, preregistered experiment (n = 25,718 from 89 countries) tested hypotheses concerning generalizable positive and negative outcomes of social distancing messages that promoted personal agency and reflective choices (i.e., an autonomy-supportive message) or were restrictive and shaming (i.e. a controlling message) compared to no message at all. Results partially supported experimental hypotheses in that the controlling message increased controlled motivation (a poorly-internalized form of motivation relying on shame, guilt, and fear of social consequences) relative to no message. On the other hand, the autonomy-supportive message lowered feelings of defiance compared to the controlling message, but the controlling message did not differ from receiving no message at all. Unexpectedly, messages did not influence autonomous motivation (a highly-internalized form of motivation relying on one’s core values) or behavioral intentions. Results supported hypothesized associations between people’s existing autonomous and controlled motivations and self-reported behavioral intentions to engage in social distancing: Controlled motivation was associated with more defiance and less long-term behavioral intentions to engage in social distancing, whereas autonomous motivation was associated with less defiance and more short- and long-term intentions to social distance. Overall, this work highlights the potential harm of using shaming and pressuring language in public health communication, with implications for the current and future global health challenges

Aquastrøm Sunnfjord. Kartlegging og detaljert beskrivelse av strømforhold og risiko for smittespredning

Det er utarbeidet en 3-dimensjonal strømmodell som detaljert beskriver strømforholdene over et 2625 km2 stort kystområde i Sunnfjord. Modellen er brukt for å utarbeide en tabell som beskriver vannkontakten mellom 32 oppdrettslokaliteter. Kontakten er ikke symmetrisk og enkelte lokaliteter kan spille en nøkkelrolle i sykdomspredning. Det er gjort en sammenligning med historiske data for sykdomsutbrudd av PD i Sunnfjord og sannsynlig smittespredning mellom lokalitetene basert på vannkontakt. Resultatene viser at modellens vannkontaktnettverk forklarer en stor andel av PD-utbruddene og at strømavstanden beskriver spredningen betydelig bedre enn både sjø- og luftavstand. Modellen har en rekke andre bruksområder innen oppdrettsnæring og forvaltning

Vurdering av lakselusindusert villfiskdødelighet per produksjonsområde i 2016 og 2017. Rapport fra ekspertgrupper for vurdering av lusepåvirkning

Ekspertgruppen ble i mars 2017 oppnevnt for ett år for å foreta en vurdering av lakselusindusert dødelighet på villfisk i 13 produksjonsområder i Norge. En foreløpig rapport basert på data fra 2016 ble levert i april 2017 og den endelige rapporten som også inkluderer data fra 2017 er ferdigstilt i september 2017. De siste data fra overvåkingssesongen 2017 kom inn medio august noe som betyr at det har vært svært kort tid frem til ferdigstilling av rapporten fra ekspertgruppen. Ekspertgruppen har i sin vurdering benyttet data fra NALO (nasjonalt overvåkningsprogram for lakselus), resultater fra modellert smittepress og resultater fra modeller som beregner smitte og dødelighet på vill laksesmolt. I tillegg kommer annen relevant litteratur. Overvåkingsdata og ulike modeller har usikkerheter og i mandatet er ekspertgruppen også bedt om å vurdere usikkerhet i alle ledd av analysen. Det er generelt høy usikkerhet knyttet til utvandringsforløp og utvandringsruter for vill laksesmolt i alle produksjonsområdene. Ekspertgruppen er samstemt i at overvåkingsdata har lavest usikkerhet og at de ulike modellene har høyere usikkerhet. Usikkerhet for de ulike modellene er beskrevet i rapporten men ekspertgruppen har ikke klart å enes om en rangering av de ulike modellene basert på usikkerhet. Ekspertgruppen er samstemt i konklusjonene og i vurderingen av usikkerhetene i alle produksjonsområdene. I 2016 ble risikoen for lakselusindusert dødelighet satt til moderat for fem produksjonsområder (PO2, PO4, PO5, PO6 og PO7), høy risiko for lakselusindusert dødelighet ble satt i ett område (PO3) og i de øvrige syv områdene ble risikoen for lakselusindusert dødelighet satt til lav (PO1, PO8, PO9, PO10, PO11, PO12 og PO13). I 2017 ble ti områder satt til å ha lav risiko for lakselusindusert dødelighet (PO1, PO2, PO6, PO7, PO8, PO9, PO10, PO11, PO12 og PO13), moderat risiko for lakselusindusert dødelighet ble satt i ett område (PO5) og høy risiko for lakselusindusert dødelighet ble satt for to områder (PO3 og PO4). Konklusjonen i PO2 og PO6 har høy usikkerhet. Framover blir det viktig å ytterliggere validere og kvantifisere usikkerheten i modellene som beregner lakselusindusert dødelighet. I denne sammenheng vil økt kunnskap om utvandringsforløp og utvandringsruter til vill laksesmolt være svært viktig. I tillegg bør man evaluere dødelighetsgrensene med nye lab-studier (benytte villaks fra ulike populasjoner) og undersøke effekten av kopepoditter og chalimus på overlevelse.publishedVersio